There were 385 people on the platform when the fire broke out. Ten persons are confirmed dead and 14 are still missing, while the rescued personnel are being brought to the mainland.

rediff.com checks out what is Bombay High and what is the impact of the oil rig disaster on ONGC.

What exactly is Bombay High?

It is India's largest offshore oil field. Situated some 161 km north of the Mumbai coast, Bombay High has a string of oil and gas rigs in the sea that pumps oil to the coast. It produces 14 per cent of India's oil requirements and accounts for 38 per cent of all domestic production.

Has the fire destroyed the whole of Bombay High?

No. The fire has destroyed only the Bombay High North platform, which used to produce 80,000 barrels of oil every day. The fire-hit platform produced about a seventh of the country's oil. (1 oil barrel = 42 gallons; 1 gallon = 3.785 litres)

The whole of Bombay High rigs have the production capacity of approximately 260,000 barrels of oil every day. ONGC has dug multiple wells over several kilometers in the Bombay High oilfield as the oil reservoirs typically extend over a large area. There are also exploratory wells probing new finds, and pipelines all over Bombay High to transport the oil.

What is the quantum of loss that the fire has destroyed?

Official statistics of what is the financial loss to ONGC due to the fire are not available. But reports say it could be as high as Rs 32,000 crore (Rs 320 billion). The platform that was gutted in the fire was insured for $195 million.

Is this the first fire on Bombay High?

No, this is the second major fire on Bombay High. There was a major fire at the gas field in 1999, but it was not as devastating as the current one.

Who discovered Bombay High?

A Russian and Indian oil exploration team that was mapping the Gulf of Cambay in 1965 in a seismic exploration vessel called Academic Arkhangelsky discovered the Bombay High oilfield.

ONGC geophysicist M Krishnamurthy headed the Indian team. According to Krishnamurthy, in those days they used explosives as source and used a 24 channel analog instrument without any magnetic record for mapping for oil fields. While they were mapping the regional line from across the Gulf of Cambay, they came across the first line where the exploration team decided to drill for oil.

But why was the place in the sea named Bombay High?

Krishnamurthy in a recent interview said that the Russian and Indian teams were in a dilemma over naming the place where they would start drilling. Then after some brainstorming, they decided to name it 'Bombay High' as it sounded rhythmic and catchy.

When did ONGC start drilling?

The company started drilling the Bombay High with the drillship Sagar Samrat in 1973 and the first well at offshore was drilled in 1974.

How many wells has ONGC drilled in Bombay High?

125, according to the company's records.

How has the Bombay High changed the stature of ONGC?

Since its inception in 1955, ONGC has been instrumental in transforming the country's limited upstream sector into a large viable playing field, with its activities spread throughout India and significantly in overseas territories. In those days, ONGC was mainly into explorations of oil in inland resources in states like Assam. The company those days also established a new oil province in Cambay basin (Gujarat), and added new petroliferous areas in the Assam-Arakan Fold Belt and East coast basins.

But ONGC went offshore in the 1970s with the discovery of Bombay High. The discovery, along with subsequent discoveries of huge oil and gas fields in Western offshore changed the oil scenario of the country. Subsequently, over 5 billion tonnes of hydrocarbons, which were present in the country, were discovered.

Has the quantity of oil produced at Bombay High been on the increase over the years?

No, in fact, the oil quantity began to decline in the 1990s.This forced the company to kick off a $1.6 billion programme aimed at extracting more oil from the ageing Bombay High in 2001. The programme was meant to produce additional 1.5 million barrels from Bombay High in the next 10 years.